Numerical and Compact Model of Metal Mesh Foil Bearings

Abstract

ABSTRACTMetal mesh foil bearings (MMFBs) are novel gas foil bearings with lower manufacturing costs and higher inherent material energy dissipation ability than traditional bump-type foil bearings. To improve the design guidelines of MMFBs and predict bearing performance, a compact theoretical model is presented by considering the metal mesh substructure as assembled springs and dry friction joints. The proposed analytical model considers the effects of several factors such as relative density, wire diameter, geometrical size, and radial interference of the metal mesh substructure. The predicted stiffness coefficients, which take the dry friction effect into account, show strong nonlinear characteristics with the increasing displacement and have a significant difference between the loading and unloading process. A series of static load tests are conducted to verify the theoretical model of MMFBs. The hysteresis loops of static load versus bearing deflection with respect to the different relative densities predicted by this model are demonstrated by experimental data. The minimum film thickness, journal eccentricity, and attitude angle with respect to different relative densities, rotational speeds, and applied loads are presented and analyzed. The predicted results of the dynamic force coefficients show that the equivalent viscous damping coefficient and relative density have significant effects on bearing dynamic performance. Furthermore, the influence of radial thickness, wire diameter, and radial interference on bearing static and dynamic performance is discussed.